Familial multiple cavernous malformation syndrome

The familial multiple cavernous malformation syndrome, or familial cerebral cavernous malformation syndrome, is uncommon, accounting for only a minority of cavernous malformations.

Epidemiology

It has been more frequently reported in patients of Hispanic descent ¹.

Diagnosis

The definition of familial multiple cavernous malformation syndrome is when there is one or more of the following ^4,5:

• multiple cerebral cavernous malformations

  • five or more cavernomas, or

  • one cavernoma and at least one other family member with one or more cavernomas

• mutations in one of the three genes, KRIT1, CCM2 or PDCD10, which are associated with this disease

Clinical presentation

The presentation is most commonly with seizures (38-55%) ¹ and focal neurological deficits, whilst recurrent large hemorrhages and headaches are less frequently encountered. 

Cutaneous lesions, including cherry hemangiomas and café au lait spots, are occasionally associated ⁶. 

Pathology

In sporadic cases up to a 3^rd of cavernous malformations are multiple. When familial the number of cavernomas is higher, typically five or more ¹ and may be as high as dozens and dozens.

Familial cases usually have an autosomal dominant pattern of inheritance with incomplete penetrance ^1,2. 

See: Zabramski classification of cerebral cavernomas.

Radiographic features

The radiographic appearance of each cavernous malformation depends on size although in many instances individuals have innumerable lesions randomly distributed throughout the brain. 

For a discussion of the radiographic appearances see: cavernous malformations.

Differential diagnosis

The differential is that of other causes of cerebral microhemorrhages, including ²:

• cerebral amyloid angiopathy: usually numerous small foci

• chronic hypertensive encephalopathy: more common in the basal ganglia

• diffuse axonal injury (DAI)

• cerebral vasculitis

• radiation vasculopathy

• hemorrhagic metastases

• Parry-Romberg syndrome ²

MRI appearance may be mimicked by:

• artificial heart valve metallic emboli (very rare)

• pneumocephalus (very rare) ³